This is the approach [Carl Bugeja] took with his Spherical Folding Propeller design which he has entered into the Open Hardware Design Challenge category of The 2018 Hackaday Prize. While at rest ...

The device takes a stack of what looks like post-card size paper in the “clip”, forms them into paper air planes by a series of rollers and folding edges and then launches them out of the end.

U.S. Navy Reserve KC-130T tankers upgraded with an eight-blade composite propeller system have been cleared to refuel a range ...